First Lieutenant Irina Pyatykh serves in the United Nations Force as communications officer for Yokohama Base and secretary to Vice-Commander Kouzuki Yuuko. She originates from Poland.

Alternatively, within the Altered Fable continuity, she appears as a foreign teacher. Alongside colleagues Alfred Walken and Irma Thesleff, she engages with Class 3-B, displaying a specific interest in student Shirogane Takeru. Within this storyline, she consumes Spirytus, a Polish distilled beverage with 96% alcohol content, serving as a subtle narrative reference to the main continuity.

Notable trivia includes her initial radio communication with Bravo-1 being the first audio element in the original visual novel's intro sequence, marking a landmark debut for the developer's distinct English dialogue approach. Multiple name spelling variations exist across official and fan materials, including Irena Piatych, イリーナ・ピャトイフ, Irina Pyatykh, and Elena Piatif within English-speaking communities, the latter used in Altered Fable.